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arXiv · 1708.03682

Critical divergence of the symmetric ($A_{1g}$) nonlinear elastoresistance near the nematic transition in an iron-based superconductor

Johanna C. Palmstrom·Alexander T. Hristov·Steven A. Kivelson·Jiun-Haw Chu·Ian R. Fisher
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Abstract

We report the observation of a nonlinear elastoresistivity response for the prototypical underdoped iron pnictide Ba(Fe$_{0.975}$Co$_{0.025}$)$_2$As$_2$. Our measurements reveal a large quadratic term in the isotropic ($A_{1g}$) electronic response that was produced by a purely shear ($B_{2g}$) strain. The divergence of this quantity upon cooling towards the structural phase transition reflects the temperature dependence of the nematic susceptibility. This observation shows that nematic fluctuations play a significant role in determining even the isotropic properties of this family of compounds.

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Johanna C. Palmstrom, Alexander T. Hristov, Steven A. Kivelson, Jiun-Haw Chu, Ian R. Fisher. 2017-08-11. Critical divergence of the symmetric ($A_{1g}$) nonlinear elastoresistance near the nematic transition in an iron-based superconductor. https://doi.org/10.1103/physrevb.96.205133

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